The diagnosis and recommendation integrated system for dry bean: Determination and validation of norms

Abstract

The Diagnosis and Recommendation Integrated System (DRIS) of interpreting results of foliar analysis is an alternative to the Critical Nutrient Level (CNL) system. DRIS uses indices of ratios of nutrient concentrations and has been found to be more accurate in predicting nutrient needs for numerous crops than the CNL system. The objectives of this research were to estimate and validate DRIS norms for dry bean (Phaseolus vulgaris L.) determined from a broad‐based data set. The previously recommended foliar CNL's of 3.0% N, 0.25% P, and 1.0% K were found to be too low to be useful in predicting responses to applied fertilizers in the test environments. Prediction based on levels of 4.7% N, 0.32% P, and 1.4% K was more accurate than with the lower CNL values. DRIS was more accurate than either set of CNL values in predicting responses to applied N, P, and K. Diagnosis with DRIS was less affected by plant age than CNL.